Instructions

Arm yourself with a telescope. Venus is like a bright star in the sky; it can be seen with the naked eye, but for scientific research technology is simply necessary.

Venus revolves around the Sun faster than the Earth, so it can be observed 2 times a day. Go to the observation point either in the morning or in the evening. In the evening Venus should be looked for, and before sunrise - to the side.

Install the telescope and make the necessary calculations. You need to understand the ecliptic plane at the moment. This is the path along which the Sun moves across the vault of heaven. Venus, like most other astronomical bodies, is best observed during its elongation period, that is, at the time when the planet is farthest from the Sun. The maximum angle between Venus and the daylight never exceeds 47 degrees. During the day, the planet of interest may not be visible due to background solar illumination. We will be able to notice it only when it deviates from the Sun by at least five degrees.

Calculate the ideal time for observation. Venus will be visible 20 minutes before sunrise and 20 minutes after sunset. It is best to observe its appearance in the sky on the day of the summer and winter solstice, that is, during the period of greatest elongation.
Every seven months, this planet turns into the brightest object in the evening sky. At this time, it glows 20 times brighter than Sirius, the largest star in the northern sky. Venus is not called the “Evening Star” for nothing. But it will not be possible to see what is happening on its surface even with the most powerful telescope due to the dense atmospheric layer and heavy clouds. Only recently, with the help of spacecraft, scientists have penetrated the mystery of the surface of the mysterious planet. She is also considered the patroness of lovers, for she is named after the goddess of love.

Modern computer technologies provide us with truly limitless possibilities. One of the most amazing things is the opportunity to feel like a real astronaut, launched into orbit and exploring our planet. Google has developed a line of software products that allow you to see planet Earth from space on your PC screen and even on your mobile phone. The Google Earth program makes it possible to see any point on the globe in the form of a map and three-dimensional image.

Instructions

The basis for such limitless possibilities was space images of different scales and resolutions, stitched into a single geoinformation space. The program provides the ability to view the same surface area at different scales and with different degrees of detail. You can feel like you're in space, flying up to ours. Install the program from google.com>earth.

Go to the main menu and familiarize yourself with the program's capabilities. In the “Acquaintance” section, you can select software products with which you will travel around our endless planet. Check out presentations where you can explore the depths of the sea and shipwrecks, see how you can see the world's city streets and surface topography in 3D, and much more.

The developers made sure that no one, even a novice Google Earth user, would be left without help and advice. In the “Training” menu item, you will be introduced to the program’s capabilities and taught how to use them. To make it easier, we offer a video tour, including a video tutorial, after which you can start working with the software product yourself and continue studying it on your own.

Built-in tips and help in the program will accompany all your actions and will help you literally every step, so don’t worry, you can handle it even if you are not very good at using a computer. Take advantage of this wonderful opportunity to see and explore our beautiful planet!

Video on the topic

Sources:

• Free version of Google Earth in 2019

The passage of Venus across the disk of the Sun is a rare astronomical phenomenon, which sometimes not even every generation can see. It was thanks to one of these passages that the Russian scientist Mikhail Lomonosov discovered the presence of an atmosphere on this planet. You can try to make your discoveries in 2012, but you need to remember that in the 21st century the inhabitants of the Earth will no longer have such an opportunity.

In 2012, for the last time in the current century, the inhabitants of the Earth will be able to witness a rare astronomical event - the transit of Venus. The very word “transit” refers to the moment of time during which one celestial body passes in front of another celestial body. Of course, transit is a relative concept and exists only for a conditional observer from a specific point. On June 6, 2012 (June 5 – in the Eastern Hemisphere), the majority of people will become such observers, and far from conventional ones.

In Russia, Venus against the background of the Sun will be able to be seen by all residents of part of the country and even a little beyond the Urals - right up to the Altai Republic. At sunrise, you will see how the planet moves across the solar disk from top to bottom and from left to right. Partial transit phenomena, if optical instruments are available, can be seen in distant Siberia, however, the conventional curve of Venus’ movement for earthlings will shift further and further towards Australia. Detailed maps and graphs of the movement of Venus relative to the earth's surface can already be found on a number of resources. However, with a little knowledge of English, you can use the primary source - the website of the US National Aeronautics and Space Administration (nasa.gov)

The transit of Venus is not only an amazing and rare phenomenon, but also dangerous. It's all about the sun itself, a direct look at which can damage the lens of the eye. It is impossible to observe the transit of Venus with the naked eye; in the absence of telescopes and binoculars with a special light-protective filter, it is best to observe this astronomical phenomenon through the glass of a welder’s shield, the floppy disk of a disassembled floppy disk, project the image of the Sun through a small hole onto the screen located behind it, and so on - rules exactly the same as during a solar eclipse.

The last time earthlings could observe the transit of Venus was only eight years ago, and at approximately the same time - June 8. But the next transit of Venus across the disk of the Sun will most likely not be seen by the living inhabitants of the planet, because it will take place in 2117.

Sources:

• All about the transit of Venus in 2012 on the NASA website

Tip 4: How scientists will observe the transit of Venus across the solar disk on June 6

On June 6, 2012, the inhabitants of planet Earth had the opportunity to observe a rare astronomical phenomenon, namely the passage of Venus across the solar disk. The transit of Venus is actually analogous to what happens during a solar eclipse. However, due to the planet’s great distance from the Earth, its apparent diameter is more than 30 times smaller than the lunar diameter, so Venus cannot cover the solar disk. She is just a small dark speck against his background.

Instructions

The cycle duration is a stable value. But the sequence of intervals between passages changes. The current one will remain in place until 2846. In subsequent years, the interval between pairs of passages will be 129.5 years.

In 2012, the “small parade” could be observed in almost all areas of the globe. The exceptions were South America, West Africa and Antarctica. In Russia, this phenomenon was observed almost everywhere, but completely only in the Far East and in the northern regions of the country.

The 2012 Venus transit was observed with great interest by scientists and amateur astronomers around the world. In particular, the orbital Hubble was involved. It was aimed at the Moon, since the intense radiation could damage its light-sensitive matrix. Scientists had to detect a change in the brightness of the Earth's satellite due to the fact that a small part of the Sun was obscured by Venus, and, using spectroscopy, study the chemical composition of its atmosphere. With the help of the experiment, it was planned to determine whether it is possible to study the atmospheres of other planets using this method.

NASA's SDO probe, Japan's Hinode and Europe's Venus Express were also involved. The latter worked with a team of scientists on Spitsbergen. The Twilight of Venus experiment was also conducted, during which scientists observed transit simultaneously from different regions of the world. In particular, it was planned to find out exactly how Mikhail Lomonosov discovered the atmosphere of Venus in 1761, and to study its composition in more detail. The transit was also observed by the crew of the International Space Station.

the sun and do not look into the eyepiece, but place a sheet of white paper at some distance from it; on the sheet you can see an enlarged image of the Sun with its spots and Venus passing by. A similar effect occurs as a result of the scattering of rays by the eyepiece.

On May 26, 1761, simultaneous observation of this astronomical phenomenon was carried out by about 100 scientists located in different parts of the globe, which made it possible to calculate the distance to the Sun. This method of calculating the astronomical unit was proposed by the famous scientist E. Halley back in 1691. According to this method, it was necessary to record from positions distant from each other the exact time from the beginning of the first touch of Venus to the edge of the solar disk until the last.

M.V. Lomonosov also took part in the observation of 1761. The planet looks like a small black circle against the background of the solar disk. At the same time, at the moment of Venus’s first “touch” of the Sun, a thin light border can be seen around it. It was precisely this that Lomonosov drew attention to, concluding that this fringe was visible due to the refraction of solar rays by gases in the planet’s atmosphere. In other words, the greatest Russian scientist made an important discovery: Venus has an atmosphere.

Orbital parameters, observation.

© Vladimir Kalanov,
website"Knowledge is power".

Introduction

Venus is almost the same size and mass as Earth. His contemporaries also discovered the presence of an atmosphere on Venus. Lomonosov correctly believed that the atmosphere of Venus is denser than the earth's.

Planet Venus

In terms of its philosophical significance, this discovery is equivalent to Galileo’s discovery of earth-like relief on the surface of the Moon. Lomonosov made this discovery on June 24, 1761, during the passage of Venus across the disk of the Sun. In anticipation of a rare phenomenon, many telescopes were aimed at the solar disk. It was necessary to capture the moments of contact between the disks of the planet and the Sun. This made it possible to clarify the distance to the Sun. When Venus entered the disk of the Sun, Lomonosov noted a slight fogging of the solar edge; when the planet approached the other edge of the disk, a bulge (“bump”) first appeared on it, and then a “cut.” Many astronomers noted the same phenomena, but Lomonosov was the first to explain them. “According to these notes,” he wrote, “the planet Venus is surrounded by a noble air atmosphere, the same (if only not more) that surrounds our globe.” In 1769, a similar explanation for the described phenomenon was given by the English astronomer N. Maskelyne, and later by others (W. Herschel, I. Schröter).

Orbit of Venus. Basic orbital parameters.

Venus's orbit is closer to the Sun than the Earth's orbit. When it is on the opposite side, its entire disk is illuminated, and when it is located between the Earth and the Sun, we see only part of the hemisphere illuminated by the Sun. For this reason, Venus, like Mercury and the Moon, there are different phases depending on its location in orbit.

Venus has an almost circular orbit, which it bypasses in 225 Earth days at a distance of 108.2 million km from the Sun (0.7233 AU). Venus rotates around its axis in 243 Earth days (sidereal circular period - 243.01 days) - the maximum time among all the planets of the solar system. Venus rotates in the opposite direction around its axis, that is, in the direction opposite to the orbital movement. If we adhere to the generally accepted theory of the formation of planets in the Solar System, we should expect the rotation of all planets in one direction both in their orbits and around their axes. The existing exceptions (the orbits of Venus and Uranus) can be explained by collisions of these planets in the early stages of formation with large celestial bodies. It is assumed that large-scale catastrophic collisions of celestial bodies could lead to changes in the orientation of the rotation axis of these planets.
Such a slow, and, moreover, reverse, rotation of the planet Venus means that, when viewed from Venus, the Sun rises and sets only twice a year, since the Venusian day is equal to 117 of ours.
Venus approaches Earth at a distance of 40 million km - closer than any other planet. In size, Venus is only slightly smaller than the Earth, and its mass is close to that of the Earth. For these reasons, Venus is sometimes called Earth's twin or sister. However, the surface and atmosphere of these two planets are completely different. The Earth has rivers, lakes, oceans and a breathable atmosphere. Venus is a searingly hot planet with a thick atmosphere that would be fatal to humans.
The average circulation speed is approximately 35.03 km/s (according to J. Kelly Beatty and Andrew Chaikin, Cambridge University Press and Sky Publishing Corp., 1990 © Sky Publishing Corp).
The orbital plane of Venus deviates by 3.394° relative to the ecliptic. And when a planet passes between the Earth and the Sun, it ends up north or south of the Sun.
The axis of rotation of Venus is almost perpendicular to the plane of its orbit, so that the northern and southern hemispheres of the planet are always illuminated by the Sun equally, i.e. There are no seasons on Venus.

Transits of Venus

The orbit of Venus is much longer and therefore its transits occur less frequently. On average, twice a century with an interval between them of approximately 8 years. That is why, since the invention of the telescope, astronomers have been able to observe transits of Venus only 7 times: in 1631, 1639, 1761, 1769, 1874, 1882, 2004. Transits of Venus are possible only in early December and June, when one of the nodes of the planet’s orbit is in front of the Sun. And this happens with a frequency of 8 and 121.5 years for one node and 8 and 105.5 years for another. The closest transit took place on June 6, 2012. Transits, like total solar eclipses, are local phenomena, that is, they are visible only in some areas of the Earth.

Observing Venus

Venus is the brightest object in the sky after the Sun and Moon and therefore Venus can be found even during the day. Venus is usually visible in the evening after sunset or in the morning before sunrise against the backdrop of dawn.

Finding Venus in the sky is easier than any other planet. Since Venus's orbit is closer to the Sun than the Earth's, in our sky Venus is never very far from the Sun. For a few weeks every seven months, Venus is the brightest object in the western sky in the evenings. Therefore, during this period it is also called the “evening star”. During these periods, the visible brilliance of Venus is 20 times greater than the brilliance of Sirius, the brightest star in the northern sky. Three and a half months later, Venus rises three hours before the Sun, becoming the brilliant "morning star" of the eastern sky. Venus can be observed approximately an hour after sunset or an hour before sunrise. The maximum angle between Venus and the Sun never exceeds 47°. The two points in the orbit at which the angle reaches this value are called the greatest eastern and greatest western elongations. If only the sky is clear, it is impossible not to detect Venus within two to three weeks near these points. It is easy to notice that Venus, like the Moon, has phases. At the points of greatest elongation, the planet looks like a tiny Moon in the half-disc phase. As Venus approaches the Earth, its apparent size increases slightly every day, and its shape gradually changes to a narrow crescent. But no features of the planet’s surface can be seen due to dense clouds.

Actually, this is one of the first questions that arises for most novice astronomy enthusiasts. Some people think that through a telescope you can see the American flag, planets the size of footballs, colored nebulae like in photographs from Hubble, etc. If you also think so, then I will immediately disappoint you - the flag is not visible, the planets are the size of peas, galaxies and nebulae are gray colorless spots. The fact is that a telescope is not just a pipe for entertainment and getting “happiness into the brain.” This is a rather complex optical device, with the correct and thoughtful use of which you will receive a lot of pleasant emotions and impressions from viewing space objects. So, what can you see through a telescope?

One of the most important parameters of a telescope is the diameter of the objective (lens or mirror). As a rule, beginners buy inexpensive telescopes with a diameter of 70 to 130 mm - so to speak, to get acquainted with the sky. Of course, the larger the diameter of the telescope lens, the brighter the image will be at the same magnification. For example, if you compare telescopes with a diameter of 100 and 200 mm, then with the same magnification (100x) the image brightness will differ by 4 times. The difference is especially noticeable when observing faint objects - galaxies, nebulae, star clusters. However, it is not uncommon for beginners to immediately purchase a large telescope (250-300 mm), then be amazed at its weight and size. Remember: the best telescope is the one through which you observe more often!

So, what can you see through a telescope? Firstly, the Moon. Our space companion is of great interest to both beginners and advanced amateurs. Even a small telescope with a diameter of 60-70 mm will show lunar craters and seas. With a magnification of more than 100x, the moon will not fit into the field of view of the eyepiece at all, that is, only a piece will be visible. As the phases change, the appearance of the lunar landscapes will also change. If you look through a telescope at a young or old moon (narrow crescent), you can see the so-called ashen light - a faint glow from the dark side of the moon caused by the reflection of earthly light from the lunar surface.

Also, through a telescope you can see all the planets of the solar system. Mercury in small telescopes will simply look like a star, but in telescopes with a diameter of 100 mm or more you can see the phase of the planet - a tiny crescent. Alas, you can catch Mercury only at a certain time - the planet is not far away from the Sun, which makes it difficult to observe

Venus, also known as the morning and evening star, is the brightest object in the sky (after the Sun and Moon). The brightness of Venus can be so high that it can be seen during the day with the naked eye (you just need to know where to look). Even in small telescopes you can see the phase of the planet - it changes from a tiny circle to a large crescent, similar to the moon. By the way, sometimes people, when looking at Venus through a telescope for the first time, think that they are being shown the moon :) Venus has a dense, opaque atmosphere, so you won’t be able to see any details - just a white crescent.

Earth. Oddly enough, the telescope can also be used for ground-based observations. Quite often people buy a telescope both as a space peeper and as a spyglass. Not all types of telescopes are suitable for ground-based observations, namely lens and mirror-lens - they can provide a direct image, while in mirror telescopes of the Newtonian system the image is inverted.

Mars. yes, yes, the same one that is visible every year on August 27 as two moons :) And people fall for this stupid joke year after year, pestering familiar astronomers with questions :) Well, Mars, even in fairly large telescopes, is visible only as a small circle, and even then only during periods of confrontation (once every 2 years). However, with 80-90 mm telescopes it is quite possible to see the darkening on the planet’s disk and the polar cap.

Jupiter - perhaps it was from this planet that the era of telescopic observations began. Looking through a simple homemade telescope at Jupiter, Galileo Galilei discovered 4 satellites (Io, Europa, Ganymede and Callisto). Subsequently, this played a huge role in the development of the heliocentric system of the world. In small telescopes you can also see several stripes on the disk of Jupiter - these are cloud belts. The famous Great Red Spot is quite accessible for observation in telescopes with a diameter of 80-90 mm. Sometimes satellites pass in front of the planet's disk, casting their shadows on it. This can also be seen through a telescope.

Jupiter with its moons - approximate view through a small telescope.

Saturn is one of the most beautiful planets, the sight of which simply takes my breath away every time, although I have seen it more than one hundred times. The presence of the ring can be seen already in a small 50-60 mm telescope, but it is best to observe this planet in telescopes with a diameter of 150-200 mm, through which you can easily see the black gap between the rings (Cassini gap), cloud belts and several satellites.

Uranus and Neptune are planets circling far from the other planets; small telescopes only look like stars. Larger telescopes will show tiny bluish-greenish disks without any detail.

Star clusters are observable objects through a telescope of any diameter. Star clusters are divided into two types - globular and open. A globular cluster looks like a round nebulous speck, which, when viewed through an average telescope (from 100-130 mm), begins to crumble into stars. The number of stars in globular clusters is very large and can reach several million. Open clusters are groups of stars, often of irregular shape. One of the most famous open clusters visible to the naked eye is the Pleiades in the constellation Taurus.

Star cluster M45 "Pleiades"

Double cluster h and χ Persei.
Approximate view in telescopes from 75..80mm.

Globular cluster M13 in the constellation Hercules - approximate view through a telescope with a diameter of 300 mm

Galaxies. These star islands can be found not only through a telescope, but also through binoculars. It is to find, not to consider. In a telescope, they look like small colorless specks. Starting from a diameter of 90-100 mm, bright galaxies can be seen to have a shape. The exception is the Andromeda Nebula, its shape can be easily seen even with binoculars. Of course, there can be no talk of any spiral arms up to a diameter of 200-250 mm, and even then they are noticeable only in a few galaxies.

Galaxies M81 and M82 in the constellation Ursa Major - an approximate view through 20x60 binoculars and telescopes with a diameter of 80-90 mm.

Nebulae. They are clouds of interstellar gas and/or dust illuminated by other stars or stellar remnants. Like galaxies, in a small telescope they are visible as faint spots, but in larger telescopes (from 100-150 mm) you can see the shape and structure of most bright nebulae. One of the brightest nebulae, M42 in the constellation Orion, can be seen even with the naked eye, and a telescope will reveal a complex gas structure that looks like puffs of smoke. Some compact, bright nebulae show color, such as NGC 6210's Turtle Nebula, which appears as a small bluish disk.

Great Orion Nebula (M42)
Approximate view through telescopes with a diameter of 80mm or more.

Planetary nebula M27 "Dumbbell" in the constellation Chanterelle.
Approximate view through telescopes with a diameter of 150...200mm.

Planetary nebula M57 "Ring" in the constellation Lyra.
Approximate view through a telescope with a diameter of 130...150mm.

Double stars. Our Sun is a single star, but many stars in the Universe are double, triple or even quadruple systems, often stars of different masses, sizes and colors. One of the most beautiful double stars is Albireo in the constellation Cygnus. To the naked eye, Albireo looks like a single star, but just look through a telescope and you will see two bright points of different colors - orange and bluish. By the way, all stars in a telescope are visible as points due to the enormous distance. All,

...except for the Sun. I warn you right away - observing the Sun without special protective equipment is very dangerous! Only with a special aperture filter, which must be securely attached to the front of the telescope. No tint films, smoked glass or floppy disks! Take care of your eyes! If all precautions are followed, even with a tiny 50-60 mm telescope you can see sunspots - dark formations on the disk of the sun. These are the places from which magnetic lines come out. Our Sun rotates with a period of about 25 days, so by observing sunspots every day, you can notice the rotation of the Sun.

Comets. From time to time, bright “tailed guests” are visible in the sky, sometimes visible even to the naked eye. In a telescope or binoculars, they are visible in the same way as galaxies with nebulae - small colorless specks. Large, bright comets have a tail and a greenish color.

If after reading this article you still have a desire to purchase a telescope, then I congratulate you, because there is another important step ahead - choosing the right telescope, but more on that in

If you already own a telescope, I recommend reading the article

Clear skies!

Brief information Mercury- the planet closest to the Sun. The average distance between Mercury and the Sun is 58 million kilometers. The planet has a highly elongated orbit. A year on Mercury lasts 88 days. The planet has a very rarefied helium atmosphere. The pressure created by such an atmosphere is 500 billion times less than the air pressure at the surface of the Earth.
Venus- the brightest object in the earth's sky after the Sun and Moon. Venus completes a full revolution around the Sun in 225 days. The period of rotation around the axis is 243 days, i.e. The length of the day is the longest among the planets. The atmosphere of Venus is 96.5% carbon dioxide and 3.5% nitrogen.
Necessary equipment From an equipment point of view, observing Mercury and Venus is not fundamentally different from observing other planets. However, there are also some nuances. For example, achromatic refractors are of little use for observing Venus, as they burden the image with greater chromatism, which is especially evident due to the dazzling brilliance of the planet. It would also be a good idea to have an equatorial mount or a mount equipped with a Go-To, since observing the lower planets can and should be done during the daytime. But the difficulty of finding a planet during the day makes it almost impossible to use conventional alt-azimuth mounts.
Details on the surface of Mercury and Venus are subtle during visual observations, and the quality of all optical components of the telescope should not be in doubt. It is recommended to have high-quality planetary eyepieces available - orthoscopic and monocentric. A set of color filters will also come in handy. Orange, red and dark red (useful on large telescopes) filters will help improve the contrast of planets when observing in the daytime and twilight skies. Green, purple and blue highlight the dark details in the planets' disks. Attention! When making daytime observations of Mercury or Venus, never look at the Sun through a telescope eyepiece or an optical finder! For more information about observing the Sun through a telescope, read the instructions for the telescope. Avoid accidentally putting the Sun in the telescope's field of view. Even a fleeting glance at the Sun can damage your vision.
Mercury When to Observe Mercury Mercury has a reputation among observers as an “elusive planet.” The fact is that among all the planets, the duration of its visibility is the shortest. Since Mercury does not move far from the Sun in its visible movement across the sky, residents of the middle northern latitudes (Russia and CIS countries, Europe, England, USA, etc.) do not have the opportunity to see the planet in the dark. In contrast, Southern Hemisphere observers are sometimes able to capture Mercury after astronomical nightfall.
The most favorable periods for observing Mercury occur at the moments of its greatest elongation (removal from the Sun), and when the planet is at its greatest height above the horizon during sunset or sunrise. In mid-northern latitudes, such moments occur in the spring during the period of eastern elongation, when Mercury is visible in the evening, or in the autumn periods of its western elongation, when the planet is visible in the morning. Observations of Mercury Most likely, your first sighting of Mercury will be a little disappointing. Compared to Jupiter, Saturn and the Moon, the planet is, to put it mildly, unattractive. Mercury is a planet for sophisticated observers who love to set themselves difficult tasks and strive to achieve great results. Moreover, many experienced amateur astronomers have never observed Mercury. But if you like to spend hours looking at dim and unremarkable galaxies, perhaps Mercury will be a new, exciting activity for you.
Observing Mercury with the naked eye or binoculars Contrary to popular belief, Mercury is quite easy to find in the sky with the naked eye. As a rule, the chances of success are quite high if you look for a planet within a week before and after its greatest elongation. They increase significantly if the atmosphere is calm and observations are not interfered with by tall buildings and city smog. In the spring, during the evening visibility period, Mercury is visible to the naked eye half an hour after sunset, low above the western horizon. Depending on the terrain and the transparency of the atmosphere, the planet can be observed for about an hour in the twilight sky. Similarly, in the fall, when morning visibility begins, Mercury can be seen 30 minutes after its rise and contemplated with the naked eye for an hour until it disappears in the rays of the rising Sun. In favorable periods, the brightness of Mercury reaches -1.3 magnitude, which is only 0.1 less than that of Sirius, the brightest star in the earth's sky. It is worth noting that the low altitude above the horizon and, as a result, the thick and seething layer of air standing in the path of light from the planet makes Mercury twinkle like other stars. Many observers have noted the planet's pink or pale pink hue—look for this the next time you observe Mercury. It is much easier to view Mercury through binoculars, especially in the first minutes after sunset, when the sky is still quite bright. Of course, you won’t be able to see the planet’s phases with binoculars, but nevertheless, this is an excellent tool for finding a planet and observing such beautiful phenomena as the approach of Mercury with other planets, as well as with bright stars and the Moon.
Observing Mercury through a telescope Typically, Mercury is accessible for telescopic observations for five weeks around its best visibility periods. But it’s worth mentioning right away that observing Mercury is not an easy task. As mentioned above, the low position of the planet above the horizon creates obstacles to its observation. Prepare for the fact that the image of the planet will constantly “sausage”, and only in rare moments, for a split second, the picture calms down and allows you to see some interesting details.
The most obvious feature is the phases of Mercury, which can be seen without much difficulty in an 80mm telescope. True, this will require increasing the telescope’s magnification to at least 100x. Near maximum elongation, i.e. the best time to observe the planet, the visible disk of Mercury is illuminated by 50% (half of the disk). It should be noted that it is almost impossible to consider the phase when the planet is illuminated by less than 30% or more than 70%, since at this time Mercury is too close to the Sun.
While discerning the phases of Mercury is not that difficult, discerning the details on its disk is not a task for the faint of heart. There are many conflicting reports about the observation of various dark spots on its surface. Some observers report that they can see detail in medium-sized telescopes, but others see nothing on the planet's disk. Of course, success depends not only on the size of the telescope and its optical qualities, but also on the experience of the observer, as well as on the observing conditions.
Sketch. Dark details on the surface of Mercury. Telescope ShK 8" Near the moments of Mercury's greatest elongation, in a 100–120 mm telescope under good atmospheric conditions, slight darkening along the terminator line can be seen. However, it is quite difficult for an untrained eye to see the finest details on its surface, so experienced observers in this case have a better chance of success.
Having a telescope with an objective diameter of more than 250 mm, you can try to discern large darkenings of the surface distant from the terminator. This fun and extremely challenging activity can be a good test of your observation skills.
Venus When to observe Venus Venus is more accessible for observation compared to Mercury. Despite the fact that, like Mercury, Venus does not move far from the Sun, the apparent angular distance between them can reach 47°. During the period of optimal visibility, Venus can be observed for several hours after sunset as the “Evening Star” or before sunrise as the “Morning Star”. For residents of the Northern Hemisphere, the best time for observations is during eastern elongation, when on spring evenings the planet can be observed until midnight. During periods close to eastern or western elongation, the planet is located high above the horizon and has greater brightness, which has a favorable effect on observation conditions. Typically, the duration of best visibility is about a month. Observations of Venus Observations of Venus with the naked eye during the daytime The easiest way to observe Venus with the naked eye is to find the planet during its rise in the morning sky and keep it in sight after sunrise for as long as possible. During favorable periods of visibility and in the presence of ideal atmospheric conditions, Venus can be kept in sight for quite a long time. The chances of success increase if you block the Sun with an artificial or natural barrier. For example, find a convenient place so that a high tree or building can block the bright Sun, but does not block the planet. Naturally, daytime searches for Venus should begin with accurate information about its position in the sky and distance from the Sun. Such data can be obtained using any planetarium program, for example StarCalc. Of course, it is quite difficult to see in the daytime sky a barely noticeable tiny area of ​​​​light, almost not distinguished from the surrounding background, which is Venus. However, there is one trick that can help catch this ghostly glow: when starting to search for a planet, the first thing you should do is look at the distant horizon for a while, and then direct your gaze to the expected place in the sky where Venus should be located. Since the eyes have the ability to maintain focus for a short period of time (in this case, focusing at infinity), your chances of seeing the planet increase.
Observing Venus through binoculars Binoculars are an excellent tool for searching for Venus and making its simplest observations. Thanks to the large field of view of binoculars, it becomes possible to observe the approach of planets to each other and to the Moon. Large astronomical binoculars - 15x70 and 20x100 - are quite capable of showing the phases of Venus when its visible disk is more than 40 "". Using binoculars it is much easier to find Venus during daylight hours. But be careful: even accidentally entering the field of view of the Sun can damage your eyes, which will lead to complete loss of vision! Searches for Venus are best carried out in good weather, when the sky is blue and distant buildings are visible on the horizon, which indicates high transparency of the atmosphere. As a guide when searching for a planet, you can choose the Moon, which is usually easily visible in a bright sky. To do this, use the planetarium program to determine in advance the day and time when the Moon and Venus will be at a short distance from each other and, taking binoculars with you, go hunting.
Phases of Venus. Photographer Chris Proctor
Observing Venus through a telescope Daytime observations of Venus Even in a small telescope, the blinding radiance of Venus reduces the overall contrast of the image, making it difficult to see its phases, and also negates all efforts to discern the finest details of the surface. One way to reduce the brightness of a planet is to observe it during the daytime. The telescope allows you to observe Venus in the daytime sky almost all year round. Only for two weeks before and after its superior conjunction the planet is inaccessible to observation due to its excessive proximity to the Sun. Owners of telescopes with the Go-To auto-pointing system can easily point the telescope at Venus using the telescope's Sun Alignment method. How to do this is described in detail in the telescope user manual. Another way to find Venus is to use a telescope on an equatorial mount that has reference circles. To do this, carefully align the mount, then point the telescope at the Sun, taking the necessary precautions (use a filter specially designed for observing the Sun or project the image onto a sheet of paper). Then align the coordinate circles according to the previously calculated equatorial coordinates of the Sun (Ra and Dec). The exact coordinates of the Sun and Venus at a given time can be calculated in advance using a planetarium program. After aligning with the Sun, slowly begin to move the telescope tube until the coordinates on the alignment circles coincide with the coordinates of Venus. Using a search eyepiece, look through the telescope and find the planet. It should be noted that it is much easier to view Venus if you carefully adjust the focus of the telescope to distant objects in advance.
Once the planet is found, higher magnification can be applied. An orange or red filter will be useful, as it can increase the contrast between Venus and the sky background, and also highlight the subtle details of the cloud cover. During the period close to inferior conjunction, Venus appears as a narrow crescent. At such moments, you can notice the appearance of the so-called horns of Venus, which outline the disk of the planet with a thin light edging. This phenomenon is caused by the scattering of sunlight in the planet's atmosphere.
A typical view of Venus through a small telescope. Sketch by Evan Bruce
Night observations of Venus Although daytime observations of Venus have several advantages, many astronomy enthusiasts prefer to observe the planet in the twilight or night sky. Of course, at this time of day there are no problems with detecting a planet in the sky, which is an obvious plus. However, there are also plenty of disadvantages. As stated above, the observer's main enemy is the blinding brilliance of Venus, which prevents the detection of subtle details in the planet's cloud cover. True, this disadvantage can be combated using a polarizing filter with variable density.
Another disadvantage is the planet’s low altitude above the horizon. As a rule, even during the best periods of visibility, at night the height of Venus above the horizon does not exceed 30°. And as you know, it is advisable to observe any object when its height is more than 30°. At this altitude, the negative influence of the atmosphere on image quality is minimized.
In general, speaking about the observation of Venus and taking into account the peculiarities of its visibility, this bar can be lowered. But it is worth keeping in mind that observing the planet during a period when its height above the horizon is less than 20° is not advisable.
Observing dark patterns in the clouds of Venus Often the disk of Venus appears to the observer as homogeneous, grayish-white and without any details. Sometimes, under good observing conditions, you can notice darkening along the terminator line. Even more rarely, some astronomy lovers manage to see dark formations that have bizarre shapes. What affects the visibility of parts? At the moment there is no clear and unambiguous answer. Most likely, a combination of factors: observation conditions, quality of equipment, and visual characteristics. Let's take a closer look at the latter.
Decades ago, it was suggested that some observers' eyes were more sensitive to the ultraviolet spectrum, allowing them to see dark streaks and formations on the planet. This assumption was subsequently confirmed by photographs taken in the ultraviolet spectrum, which showed the presence of details not visible in ordinary photographs. Again, one should not discount the self-deception of the observer. The fact is that dark features are extremely elusive - it is easy to convince yourself of their presence just because you expect to see them. It is also difficult to answer the question of the minimum telescope required to observe the details of the cloud cover. Some observers claim that they see them in 100-mm telescopes, while others cannot see them even in larger ones. Some observers are able to see the darkening using a blue, violet, or yellow filter. Therefore, regardless of the equipment you have, do not stop trying to find interesting features, train your eyes, and luck will definitely smile on you.
There is the following classification of dark features: Tape. Dark, parallel stripes. They run perpendicular to the edge of the horns. Radial. Dark stripes extending radially from the subsolar point (the place where the sun's rays hit at right angles). Incorrect. They have a vague shape, can be either elongated or almost straight. Amorphous. Chaotic darkening that has no shape and cannot be described.
White (bright) spots on Venus Sometimes it is possible to observe bright spots near the poles of the planet. So-called “polar spots” can be observed for several weeks and are usually characterized by a slow appearance and an equally slow disappearance. Spots often appear near the South Pole, less often near the North Pole.
Sketches of Venus in a 100mm reflector. Dark and light formations and irregularities of the terminator are visible.
Anomalies Schröter effect The so-called Schröter effect consists of a delay or advance of the onset of the moment of dichotomy (phase 0.5) by several days relative to preliminary calculations. Observed near the lower planets (Mercury and Venus). The reason for this phenomenon lies in the scattering of sunlight along the planet's terminator.
Ash Light Another interesting illusion occurs when Venus is in a narrow crescent phase. Sometimes during these periods you can notice a slight glow in the unlit part of the planet.
Contour unevenness Combinations of dark and bright details, which appear more clearly near the terminator line, create the illusion of unevenness. This phenomenon is difficult to notice visually, but usually shows up well in photographs of Venus. The planet becomes like a piece of cheese, as if carefully gnawed by mice from the edge (near the terminator).

Venus comes closer to Earth than any other planet. But the dense, cloudy atmosphere does not allow you to directly see its surface. Radar images show a very wide variety of craters, volcanoes and mountains.
Surface temperatures are hot enough to melt lead, and the planet may once have had vast oceans.

Venus is the second planet from the Sun, having an almost circular orbit, which it goes around in 225 Earth days at a distance of 108 million km from the Sun. Venus rotates around its axis in 243 Earth days—the longest time among all the planets. Around its axis, Venus rotates in the opposite direction, that is, in the direction opposite to its orbital movement. Such a slow, and, moreover, backwards rotation means that, when viewed from Venus, the Sun rises and sets only twice a year, since the Venusian day is equal to 117 of ours. Venus approaches Earth at a distance of 45 million km - closer than any other planet.

Venus is only slightly smaller in size than Earth, and its mass is almost the same. For these reasons, Venus is sometimes called Earth's twin or sister. However, the surface and atmosphere of these two planets are completely different. On Earth there are rivers, lakes, oceans and the atmosphere that we breathe. Venus is a searingly hot planet with a thick atmosphere that would be fatal to humans.

Before the start of the space age, astronomers knew very little about Venus. Thick clouds prevented them from seeing the surface through telescopes. The spacecraft managed to pass through the atmosphere of Venus, which consists mainly of carbon dioxide with admixtures of nitrogen and oxygen. Pale yellow clouds in the atmosphere contain droplets of sulfuric acid that fall on the surface as acid rain.

Finding Venus in the sky is easier than any other planet. Its dense clouds perfectly reflect sunlight, making the planet bright. Since Venus's orbit is closer to the Sun than the Earth's, Venus in our sky never moves very far from the Sun. For a few weeks every seven months, Venus is the brightest object in the western sky in the evenings. It is called the "evening star". During these periods, the saw-like brilliance of Venus is 20 times greater than the brilliance of Sirius, the brightest star in the northern sky. Three and a half months later, Venus rises three hours earlier than the Sun, becoming the brilliant "morning star" of the eastern sky.

You can observe Venus about an hour after sunset or an hour before sunrise. The angle between Venus and the Sun never exceeds 47°. Within two to three weeks, it is impossible not to detect Venus near these points, unless the sky is clear. If you first see Venus in the predawn sky during the period of greatest western elongation, you will be able to distinguish it later, even after sunrise, it is so bright. If you are using binoculars or a telescope, take the necessary precautions to ensure that the Sun does not accidentally enter your field of view.

It is easy to see that Venus, like Lupe, has phases. At the points of greatest elongation, the planet looks like a tiny Moon in the half-disc phase. As Venus approaches the Earth, its apparent size increases slightly every day, and its shape gradually changes to a narrow crescent. But no features of the planet’s surface can be seen due to dense clouds.

Transit of Venus across the Sun

It very rarely happens that Venus passes exactly between the Earth and the Sun. These passages were used in the 18th century. to determine the size of the solar system. By noting the time difference between the beginning and end of the passage when observed from different points on the Earth, astronomers estimated the distance between Earth and Venus. Captain Cook's third voyage of discovery (1776–1779) included observation of the passage. The next time Venus will cross the solar disk is in 2004.

Phases of Venus

Galileo was the first to observe the phases of Venus in 1610. From the similarity with the phases of the Moon, he concluded that the orbit of Venus is closer to the Sun than the orbit of the Earth. His observations of Venus proved that the Sun was at the center of our solar system. By observing the phases of Venus every few days for about a month, you can calculate whether this planet is approaching us or moving away from us.

Hot world

The atmosphere of Venus is extremely hot and dry. The surface temperature reaches its maximum at approximately 480°C. The atmosphere of Venus contains 105 times more gas than the atmosphere of Earth. The pressure of this atmosphere at the surface is very high, 95 times higher than on Earth. Spaceships have to be designed to withstand the crushing, crushing force of the atmosphere. In 1970, the first spacecraft to arrive on Venus was able to withstand the intense heat for only about one hour, just long enough to send data back to Earth about conditions on the surface. Russian aircraft that landed on Venus in 1982 sent color photographs of sharp rocks to Earth.

Thanks to the greenhouse effect, Venus is extremely hot. The atmosphere, which is a dense blanket of carbon dioxide, retains the heat coming from the Sun. As a result, such an amount of thermal energy accumulates that the temperature of the atmosphere is much higher than in the oven.

On Earth, where the amount of carbon dioxide in the atmosphere is small, the natural greenhouse effect increases the global temperature by 30°C. And on Venus, the greenhouse effect raises the temperature by another 400°C. By studying the physical consequences of the strong greenhouse effect on Venus, we begin to imagine the results that could result from the accumulation of excess heat on Earth, caused by the growing concentration of carbon dioxide in the atmosphere due to the burning of fossil fuels - coal and oil.

Venus and Earth in ancient times

4.5 billion years ago, when the Earth first formed, it also had a very dense atmosphere of carbon dioxide - just like Venus. This gas, however, dissolves in water. Earth was not as hot as Venus because it is further from the Sun; As a result, the rains washed carbon dioxide out of the atmosphere and sent it into the oceans. Rocks such as chalk and limestone, which contain carbon and oxygen, arose from the shells and bones of sea animals. In addition, carbon dioxide was extracted from the atmosphere of our planet during the formation of coal and oil. There is not much water in the atmosphere of Venus. And due to the greenhouse effect, the temperature of the atmosphere exceeds the boiling point of water up to an altitude of about 50 km. It’s possible that Venus once had oceans in the past, but if there were, they boiled away long ago.

Surface of Venus

To study the nature of the surface of Venus under a thick layer of clouds, astronomers use both interplanetary spacecraft and radio waves. More than 20 American and Russian spacecraft have already been sent to Venus - more than to any other planet. The first Russian ship was crushed by the atmosphere. However, in the late 1970s - early 1980s. The first photographs were obtained, in which formations of hard rocks are visible - sharp, sloping, crumbling, small chips and dust. - the chemical composition of which was similar to the volcanic rocks of the Earth.

In 1961, scientists sent radio waves to Venus and received the reflected signal on Earth, measuring the speed of the planet's rotation around its axis. In 1983, the spacecraft Veiera-15 and Venera-16 entered orbit around Venus.

Using radar, they built a map of the northern hemisphere of the planet to parallel 30". Even more detailed maps of the entire surface with details up to 120 m in size were obtained in 1990 by the Magellan ship. Using computers, radar information was turned into images similar to photographs, where volcanoes, mountains and other landscape details are visible.

Impact craters

"Magellan" transmitted beautiful images of huge Venusian craters to Earth. They arose as a result of the impacts of giant meteorites that broke through the atmosphere of Venus onto its surface. Such collisions released liquid lava trapped inside the planet. Some meteorites exploded in the lower atmosphere, creating shock waves that formed dark, circular craters. Meteorites passing through the atmosphere travel at speeds of about 60,000 km/h. When such a meteorite hits the surface, the solid rock instantly turns into hot steam, leaving a crater in the ground. Sometimes lava after such an impact finds its way up and flows out of the crater.

Volcanoes and lava

The surface of Vspori is covered with hundreds of thousands of volcanoes. There are several very large ones: 3 km high and 500 km wide. But most of the volcanoes are 2-3 km across and about 100 m in height. The outpouring of lava on Venus takes much longer than on Earth. Venus is too hot for ice, rain, or storms, so there is no significant weathering. This means that volcanoes and craters have hardly changed since they were formed millions of years ago. In the photographs of Venus taken from Magellan, we see such an ancient landscape that you will not see on Earth - and yet it is younger than on many other planets and loops.

Apparently Venus is covered in solid rock. Hot lava circulates underneath them, causing tension in the muddy surface layer. Lava constantly erupts from holes and fractures in solid rock. In addition, volcanoes constantly emit jets of small droplets of sulfuric acid. In some places, thick lava, gradually oozing, accumulates in the form of huge puddles up to 25 km wide. In other places, huge paw bubbles form domes on the surface, which then fall off.

On Earth, it is not easy for geologists to figure out the history of our planet, since mountains and valleys are constantly being eroded by wind and rain. Venus is of great interest to scientists because its surface is similar to ancient fossil layers. Details of its landscape discovered by Magellan are hundreds of millions of years old.

Volcanoes and lava flows remain constant on this dry planet, the world closest to ours.